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Initial stages of GaAs/au eutectic alloy formation for the growth of GaAs nanowires

Rosnita M, Yussof W, Zuhairi I, Zulkafli O, Samsudi S

Sains Malaysiana, 2012;41:1133-1138.

Annealing temperature plays an important role in the formation of an Au-Ga eutectic alloy. The effects of the annealing temperature on gold nanoparticles colloid and substrate surface were studied using AFM, FE-SEM and TEM. At 600oC, the layer of gold colloids particle formed an island in the state of molten eutectic alloy and absorbed evaporated metalorganics to formed nanowire (NW) underneath the alloy. Pit formed on the substrate surface due to the chemical reactions during the annealing process have an impact on the direction of growth of the NW. Without annealing, the NW formed vertically on the GaAs (100) surface. The growth direction depends on the original nucleation facets and surface energy when annealed. When annealed, the wire base is large and curved due to the migration of Ga atoms on the substrate surface towards the tip of the wire and the line tension between the substrate surface and gold particle.

Matched MeSH terms: Gallium
Structural properties of zinc oxide thin films deposited on various substrates

Ching C, Om P, Ng S, Hassan Z, Abu Hassan H, Abdullah M

Sains Malaysiana, 2014;43:923-927.

In this work, the structural properties of radio frequency sputtering-grown zinc oxide (ZnO) thin films on sapphire (Al203), gallium arsenide (GaAs) and n-type silicon (Si) substrates were characterized. Scanning electron microscopy was employed to study the surface morphology of the samples. X-ray diffraction (xRD) measurements were also performed to obtain the structural information of the samples. The xRD results showed that the ZnO layers grown on different substrates have similar lattice constant (c) values, which were used to calculate the strain percentages of the ZnO thin films. The surface morphologies of the ZnO thin films indicated the formation of a granular surface when ZnO is deposited on n-type Si(100) and Si( 111 ) substrates. Meanwhile, a leaf-like surface is obtained when ZnO is deposited on GaAs and Al203 substrates. The results showed that the ZnO thin film grown on n-type Si(100) has the best quality among all the samples.

Matched MeSH terms: Gallium
68Ga-prostate specific membrane antigen-11 PET/CT versus multiparametric MRI in the detection of primary prostate cancer: A systematic review and head-to-head comparative meta-analysis

Ren X, Nur Salihin Yusoff M, Hartini Mohd Taib N, Zhang L, Wang K

Eur J Radiol, 2024 Jan;170:111274.
PMID: 38147764 DOI: 10.1016/j.ejrad.2023.111274

PURPOSE: The goal of this study was to evaluate the effectiveness of two diagnostic methods, 68Ga-PSMA-11 PET/CT and mpMRI, in detecting primary prostate cancer without limitations on the Gleason score.
METHODS: We conducted a comprehensive literature review, searching databases such as PubMed, Embase, and Web of Science until June 2023. Our objective was to identify studies that compared the efficacy of 68Ga-PSMA-11 PET/CT and mpMRI in detecting primary prostate cancer. To determine heterogeneity, the I2 statistic was used. Meta-regression analysis and leave-one-out sensitivity analysis were conducted to identify potential sources of heterogeneity.
RESULTS: Initially, 1286 publications were found, but after careful evaluation, only 16 studies involving 1227 patients were analyzed thoroughly. The results showed that the 68Ga-PSMA-11 PET/CT method had a pooled sensitivity and specificity of 0.87 (95 % CI: 0.80-0.92) and 0.80 (95 % CI: 0.69-0.89), respectively, for diagnosing prostatic cancer. Similarly, the values for mpMRI were determined as 0.84 (95 % CI: 0.75-0.92) and 0.74 (95 % CI: 0.61-0.86), respectively. There were no significant differences in diagnostic effectiveness observed when comparing two primary prostate cancer methodologies (pooled sensitivity P = 0.62, pooled specificity P = 0.50). Despite this, the funnel plots showed symmetry and the Egger test results (P values > 0.05) suggested there was no publication bias.
CONCLUSIONS: After an extensive meta-analysis, it was found that both 68Ga-PSMA-11 PET/CT and mpMRI demonstrate similar diagnostic effectiveness in detecting primary prostate cancer. Future larger prospective studies are warranted to investigate this issue further.

Matched MeSH terms: Gallium Radioisotopes
Antibacterial properties of poly (octanediol citrate)/gallium-containing bioglass composite scaffolds

Zeimaran E, Pourshahrestani S, Djordjevic I, Pingguan-Murphy B, Kadri NA, Wren AW, et al.

J Mater Sci Mater Med, 2016 Jan;27(1):18.
PMID: 26676864 DOI: 10.1007/s10856-015-5620-2

Bioactive glasses may function as antimicrobial delivery systems through the incorporation and subsequent release of therapeutic ions. The aim of this study was to evaluate the antimicrobial properties of a series of composite scaffolds composed of poly(octanediol citrate) with increased loads of a bioactive glass that releases zinc (Zn(2+)) and gallium (Ga(3+)) ions in a controlled manner. The antibacterial activity of these scaffolds was investigated against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The ability of the scaffolds to release ions and the subsequent ingress of these ions into hard tissue was evaluated using a bovine bone model. Scaffolds containing bioactive glass exhibited antibacterial activity and this increased in vitro with higher bioactive glass loads; viable cells decreased to about 20 % for the composite scaffold containing 30 % bioactive glass. The Ga(3+) release rate increased as a function of time and Zn(2+) was shown to incorporate into the surrounding bone.

Matched MeSH terms: Gallium*
The role of 67gallium scintigraphy and high resolution computed tomography as predictors of disease activity in sputum smear-negative pulmonary tuberculosis

Lai FM, Liam CK, Paramsothy M, George J

Int J Tuberc Lung Dis, 1997 Dec;1(6):563-9.
PMID: 9487455

University Hospital, Kuala Lumpur, Malaysia.

Matched MeSH terms: Gallium Radioisotopes*
Fulltext Mastoiditis secondary to mycobacterium abscessus imaged with gallium-67 scintigraphy

Vijayananthan A, Arumugam A, Kumar G, Harichandra D

Biomed Imaging Interv J, 2008 Apr;4(2):e23.
PMID: 21614326 MyJurnal DOI: 10.2349/biij.4.2.e23

Atypical mycobacterium is rarely seen as a cause of chronic mastoiditis but has been increasingly recognized over the past few years. Mycobacterium abscessus is the most pathogenic and chemotherapy-resistant, rapid-growing mycobacterium of all the four groups. This paper presents a case of a 57-year-old woman who had chronic mastoiditis with recurrent exacerbations. The initial computed tomography (CT) findings showed the presence of an inflammatory process and she was treated with the appropriate antibiotics. The patient subsequently underwent a tissue biopsy when she presented with another exacerbation. At this time, the CT scan did not identify the ongoing exacerbation, but the Gallium-67 scintigraphy did.

Matched MeSH terms: Gallium Radioisotopes
Fulltext A Case of Appendiceal Goblet Cell Carcinoid Tumor: Getting it right under the Microscope

Kang WH, Wahab NA, Kamaruddin NA

J ASEAN Fed Endocr Soc, 2020;35(1):102-104.
PMID: 33442175 DOI: 10.15605/jafes.035.01.16

Goblet cell carcinoid (GCC) is a rare neoplasm of the vermiform appendix and can be mistaken as a typical neuroendocrine tumour (TNET). The natural history of this disease is more aggressive compared to TNETs and requires a more aggressive approach. We report a case of a 37-year-old male who was initially diagnosed with TNET, but subsequently revised as Tang's A GCC. He underwent appendectomy and right hemicolectomy. Aside from a persistently elevated carcinoembyrogenic antigen (CEA) result, his 18F-fluorodeoxyglucose (FDG) PET/CT and a 68-Gallium DOTATATE PET/CT scan showed no FDG or DOTATATE avid lesions.

Matched MeSH terms: Gallium Radioisotopes
Fulltext Gallium scan in diagnosing ocular sarcoidosis

Ismail S, Embong Z, Hitam WH

Malays J Med Sci, 2005 Jan;12(1):64-7.
PMID: 22605949

A 40-year-old man presented with floaters and painless progressive blurring of vision in the right eye for one month duration. Visual acuity in the right eye was 6/24. There was mild anterior chamber reaction and vitritis. The optic disc was swollen and elevated with presence of granulomatous lesion in the optic disc head. Blood investigations were unremarkable. Serum angiotensin converting enzyme (ACE) was normal and conjunctival biopsy showed presence of inflammatory cells. B-Scan ultrasound revealed an echo-dense lesion in the optic nerve head. There was increased uptake of the right lacrimal gland and presence of 'Panda sign' with Gallium scan. A diagnosis of right ocular sarcoidosis was made base on the clinical features and Gallium scan.

Matched MeSH terms: Gallium
Fulltext Use of gallium-67 in the assessment of response to antibiotic therapy in malignant otitis externa--a case report

Paramsothy M, Khanijow V, Ong TO

Singapore Med J, 1997 Aug;38(8):347-9.
PMID: 9364890

Malignant Otitis Externa (MOE) can cause considerable morbidity and mortality in affected individuals. The outlook is now much improved with the use of ciprofloxacin, but it is important to ascertain that the infection has been completely eradicated before stopping treatment, as undertreatment may lead to a recurrence which is usually more resistant than the initial infection. Gallium-67 Single Photon Emmision Computerised Tomography (SPECT) is a sensitive and cost effective tool in monitoring the disease activity of MOE, and should be used in the assessment of the response to antibiotic therapy.

Matched MeSH terms: Gallium Radioisotopes*
The quantification of PET-CT radiotracers to determine minimal scan time using quadratic formulation

Said MA, Musarudin M, Zulkaffli NF

Ann Nucl Med, 2020 Dec;34(12):884-891.
PMID: 33141408 DOI: 10.1007/s12149-020-01543-x

OBJECTIVE: 18F is the most extensively used radioisotope in current clinical practices of PET imaging. This selection is based on the several criteria of pure PET radioisotopes with an optimum half-life, and low positron energy that contributes to a smaller positron range. In addition to 18F, other radioisotopes such as 68Ga and 124I are currently gained much attention with the increase in interest in new PET tracers entering the clinical trials. This study aims to determine the minimal scan time per bed position (Tmin) for the 124I and 68Ga based on the quantitative differences in PET imaging of 68Ga and 124I relative to 18F.
METHODS: The European Association of Nuclear Medicine (EANM) procedure guidelines version 2.0 for FDG-PET tumor imaging has adhered for this purpose. A NEMA2012/IEC2008 phantom was filled with tumor to background ratio of 10:1 with the activity concentration of 30 kBq/ml ± 10 and 3 kBq/ml ± 10% for each radioisotope. The phantom was scanned using different acquisition times per bed position (1, 5, 7, 10 and 15 min) to determine the Tmin. The definition of Tmin was performed using an image coefficient of variations (COV) of 15%.
RESULTS: Tmin obtained for 18F, 68Ga and 124I were 3.08, 3.24 and 32.93 min, respectively. Quantitative analyses among 18F, 68Ga and 124I images were performed. Signal-to-noise ratio (SNR), contrast recovery coefficients (CRC), and visibility (VH) are the image quality parameters analysed in this study. Generally, 68Ga and 18F gave better image quality as compared to 124I for all the parameters studied.
CONCLUSION: We have defined Tmin for 18F, 68Ga and 124I SPECT CT imaging based on NEMA2012/IEC2008 phantom imaging. Despite the long scanning time suggested by Tmin, improvement in the image quality is acquired especially for 124I. In clinical practice, the long acquisition time, nevertheless, may cause patient discomfort and motion artifact.

Matched MeSH terms: Gallium Radioisotopes/chemistry
Fulltext Effective Dose Estimation of Patients Administered with 18F-FDG and Ga-68 DOTATATE in PET/CT Examination Associated with Gender and Weight

Kamal, I., Said, M. A., Bathumalai, J., Abdul Razak, H. R., Abdul Karim, M. K.

Physics and Technology in Medicine, 2020;1(1):15-21.
MyJurnal

The whole-body fluorodeoxyglucose F18 (18F-FDG) and gallium-68 (Ga-68 DOTATATE) are the most common radiopharmaceutical use in PET/CT imaging for cancer staging. Although radiopharmaceutical for PET/CT examination has been acknowledged for its safety and efficacy, the internal dosimetry and effective dose (ED) from the examinations are rarely discussed. Hence, this study aimed to evaluate radiation ED for whole-body radiopharmaceuticals PET/CT concerning patients’ gender and their weight. A total of 82 oncology patients (44 males and 38 females) were collected retrospectively from Institut Kanser Negara, Putrajaya. Data, such as 18F-FDG and Ga-68 DOTATATE activity and patient demography (weight, height, age), were recorded and analyzed. Effective doses from both internal and external exposure were calculated using the coefficient
provided by the International Commission on Radiological Protection (ICRP) report. The total ED of 18F-FDG for male patients was 20.2 ± 8.6 mSv and for female patients were 19.0 ± 8.2 mSv while total whole-body ED for Ga-68 DOTATATE for male patients was 18.5 ± 7.0 mSv and 17.0 ± 5.6 mSv for female patients. The ratio for ED between male and female were 1:1 for both examinations ranged from 12.0 – 23 mSv. From this study, it indicated that the ED of Ga-68 DOTATATE was far lower when compared to the ED of 18F-FDG by a factor of 0.7. Therefore, it is crucial to optimize the PET/CT protocol dose in order to uphold the dose as low as reasonably achievable (ALARA).

Matched MeSH terms: Gallium Radioisotopes
Fulltext Neuroendocrine tumour of the lung: a diagnostic challenge

Nur Hidayah Bahrom, Anis Safura Ramli, Nor Suraya Samsudin, Norliana Dalila Mohamad Ali, Nor Salmah Bakar

Journal of Clinical and Health Sciences, 2019;4(2):97-104.
MyJurnal

This is a case of a 62-year-old Indian man who was diagnosed with a rare type of lung
neuroendocrine tumour (NET) of atypical carcinoid (AC) subtype which comprises only 0.1%–
0.2% of pulmonary neoplasms. He initially presented to a private hospital in May 2018 with a
6-month history of chronic productive cough and haemoptysis. Chest X-Ray (CXR), CT scan,
bronchoscopy, biopsy and broncho-alveolar lavage were conducted. At this stage, imaging and
histopathological investigations were negative for malignancy. Diagnosis of bronchiectasis was
made and he was treated with antibiotic and tranexamic acid. Due to financial difficulties, his
care was transferred to a university respiratory clinic in June 2018. His condition was monitored
with CXR at every visit and treatment with tranexamic acid was continued for 6 months.
However, due to persistent haemoptysis, he presented to the university primary care clinic in
Dec 2018. Investigations were repeated in January 2019 where his CXR showed increased
opacity of the left retrocardiac region and CT scan revealed a left lower lobe endobronchial
mass causing collapse with mediastinal lymphadenopathy suggestive of malignancy.
Bronchoscopy, biopsy and histopathology confirmed the presence of NET. Although the Ki-67
index was low, the mitotic count, presence of necrosis and evidence of liver metastases
favoured the diagnosis of AC. A positron emission tomography Ga-68 DONATOC scan showed
evidence of somatostatin receptor avid known primary malignancy in the lungs with suspicions
of liver metastasis. He was subsequently referred to the oncology team and chemotherapy was
initiated. This case highlights the challenge in diagnosis and management of patients with AC.
Physicians ought to be vigilant and have a high index of suspicion in patients who present with
persistent symptoms on multiple visits. Early diagnosis of NET would prevent metastasis and
provide better prognosis. Continuous follow-up shared care between primary care and
secondary care physicians is also essential to provide ongoing psychosocial support for
patients with NET, especially those with metastatic disease

Matched MeSH terms: Gallium Radioisotopes